Vortex combustor

ABSTRACT

A vortex combustor of high efficiency, intensity and stability comprises a first cylindrical combustion chamber having an inlet means, a fuel supplying device and an igniting device, a second cylindrical combustion chamber having a throttled open part, and a connecting part having a throttled opening to connect the first combustion chamber and second combustion chamber, thereby to form respectively a forced vortex zone in the central region and a natural vortex zone in the outer region surrounding said central region of each of the first and second cylindrical combustion chambers with swirling air introduced through said inlet means, and to burn the mixture of air and fuel in the forced vortex zone of the first cylindrical combustion chamber and in the natural vortex zone of the second cylindrical combustion chamber.

United States Patent 1 Tanasawa VORTEX COMBUSTOR [75] Inventor: YasusiTanasawa, Nagoya, Japan [73] Assignee: Kabushiki Kaisha Toyota ChuoKenkyusho, Nagoya-shi, Japan [22] Filed: Apr. 3, 1972 [21] Appl. No.:240,699

[30] Foreign Application Priority Data Apr. 1', 1971 Japan 46-20623 [52]US. Cl. 60/39.65, 60/3966, 60/3916 R, 60/39.72 R, 60/269, 60/271,431/351 [51] Int. Cl. F02g 7/04 [58] Field of Search 60/3965, 39.23,39.29, 60/3966, 39.72 R

[56] References Cited UNITED STATES [PATENTS 3,175,361 3/1965 Schirmer60 3965 x 2,935,840 5/1960 Schoppe 60/3965 x 3,082,603 '3/1963Hering...; 60/39.65 2,195,025 3/1940 CouzinetL... 60/39.65

1,069,243 8/1913. Fogler 60/39.65 ux 3,016,703 1 1962 LOI'CII 60/3965 [41 May 7,1974

2,601,000 6/1952 Nerad 60/3965 2,659,201 11/1953 Krejci 2,867,267 l/l959Nerad 60/3965 X Primary Examiner-Clarence R. Gordon Attorney, Agent, orFirm0blon, Fisher, Spivak, Mc- Clelland & Maier [5 7] ABSTRACT the outerregion surrounding said central region of each of the first and secondcylindrical combustion chambers with swirling air introduced throughsaid inlet means, and to burn the mixture of air and fuel in the forcedvortex zone of the first cylindrical combustion chamber and in thenatural vortex zone of the I second cylindrical combustion chamber.

20 Claims, 17 Drawing Figures PATENTEDIM 7 I974 SHEET 1 BF 3 T R A R l RP PRIOR ART PRIOR ART PRIOR ART :ATENTED MAY 7 i974 SHEET 2 OF 3PATENTEDHAY 11914 v 3.808 802 sum 3 or 3 VORTEX COMBUSTOR BACKGROUND OFTHE INVENTION 1. Field of the Invention The present invention relates toa vortex combustor which can be used for various purposes such as forhome use, for industrial use, for gas turbines and for jet engines.

2. The Prior Art In case of the various conventional combustors,-because of their structure and severe operating condition, only in thenarrow range of air-fuel ratio, the combustion efficiency and thecombustion intensity (the weight of fuel which can be burned per unittime in the unit volume,or calorific value of the said fuel; kcal/mhr-atm) can be kept high in some degree. In the case of such combustorsdesigned for gas turbines and for. jet engines, it is necessary tosupply a large amount of air into the combustion chamber in proportionto its output. If this air flow increases, combustion flame does notspread to the whole inside wall of the combustion chamber, and themixture of air and fuel is not burned with high intensity,so thecombustion efficiency and the combustion intensity becomes low. Whilethere have been many studies about vortex combustors, a satisfactorycombustor for practical use has not yet been provided, mainly because ofthe fact that these studies haven't cleared up some of the importantcharacteristics of vortex combustors.

SUMMARY or THE INVENTION Accordingly, it is an object of the presentinvention to provide a novel and useful vortex combustor. Another objectof the present invention is to provide a vortex combustor having bothhigh combustion efficiency and high combustion intensity.

Another object of the present invention is to provide a vortex combustorproviding easy ignition and stable 'BRIEF DESCRIPTION OF THE DRAWINGSVarious other objects,f eatures and attendant advantages of the presentinvention will be more fully appreciated as the same becomes betterunderstood from the following detailed description when considered inconnection with the accompanying Drawings, wherein like referencenumerals designate like or corresponding parts throughout the severalFigures, and in which:

FIG.1 is a perspective view showing the construction of a conventionalvortex combustor and its operating principle;

FIG. 2 is a vertical cross-sectional view of the vortex combustor ofFIG.1;

FIG. 3 is a cross-sectional view showing the operating condition of thenatural vortex in the combustion of a conventional vortex combustor;

FIG. 4 is the cross-sectional view showing the operating condition ofthe forced vortex in the combustion chamber of a conventional vortexcombustor;

FIG. 5 is a partially cut-away perspective view showing the constructionof a vortex combustor according to one embodiment of the presentinvention;

FIG. 6 is the vertical cross-sectional view of FIGS,

taken along the line VIVI thereof;

FIG. 7 is a cross-sectional view of FIG. 6 taken alon the line VIIVIIthereof;

FIG. 8 is a cross sectional view of FIG. 6 along the line VIIIVIIIthereof;

FIG. 9 is a view showing the first embodiment in which the vortexcombustor of the present invention is applied to a gas turbine engine;

FIG. 10 is an explanatory view showing the spiral flowing condition inthe combustion chamber of the vortex combustor of the present invention;

FIGS. llA-llF are explanatory views showing the progressive combustionconditions in the combustion chamber of the vortex combustor of thepresent invention; and

FIG. 12 is a view showing a second embodiment of the present inventionin which the vortex combustion thereof is applied to another gas turbineengine.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS Under all operatingconditions, the transition of the flame in the forced vortex zone nearthe center of the combustion chamber to the natural vortex formedbetween the outer surface of the forced vortex zone and the innersurface wall of the combustion chamber takes place very easily, and thusthe mixture of air and fuel can be completely burned with highintensity. Thus, the combustion efficiency and the combustion intensityof the vortex combustorcan be greatly increased. Many problems in gasturbines and in jet enginges,such as the difficult ignition of themixture of air and fuel, the blow-out of the flame,local overheating inthe combustion chamber,and the complication of the structure, canaccordingly now be resolved.

Hereafter,the various characteristics of a vortex combustor are closelyexplained.

As shown both in FIGS. 1 and 2, the cylindrical combustion chamber 1 ofa conventional vortex combustor A is provided with an air inlet passage2 having an air flow inlet port 3 which opens in such a manner that itsaxial direction coincides with the tangential direction of the innerperipheral surface of the chamber so that high pressure air beingsupplied into the combustion chamberl is given a swirling motion in acounterclockwise direction, the center of which is the axis of thecylindrical combustion chamber 1.

Near the center of the closed upper end wall 5 of the cylindricalcombustionchamber 1, an ignition device 7 connected with an ignitionenergy source, now shown, is provided, with the ignition electrode 6thereof being projected down into the combustion chamber 1. A fuelinjection nozzle 9 connected to a fuel source, not shown, is alsoprovided near the ignition device 7, and the injection hole 8 of nozzle9 opens into the combustion chamber.

A lower wall part 10 opposing the closed wall 5 of the combustionchamber 1 has an exhaust hole 1 1 provided coaxially therein. Inoperation, compressed air is conducted tangentially into the combustionchamber 1, where it is mixed with fuel, and after being ignited andburned, the combustion gas is conducted out through the. exhaust hole11.

Now, to explain the operation of the conventional vortex combustor Ashown in FIGS. 1 and 2, the radius of the exhaust hole 11 is shown as rr is the radius of the combustion chamber 1, and h is the height of thecombustion chamber.

When air of pressure P0 is supplied into the combustion chamber 1, thecompressed air of specific weight 7 flows tangentially into thecombustion chamber of radius r with a tangential velocity [14 from airinlet hole 3 of cross-sectional area S whereupon the compressed airswirls in the combustion chamber 1 and traces a spiral line 12. Duringthis process, the pressure energy P/y is converted tethe velocity energyu /2 g, an d t h eg the tangential velocity u gradually, increases. Inthe case of an ideal fluid without viscosity, the law of the naturalvortex u r ur holds,so that the tangential velocity u increasesinversely as the radius r decreases.

When the radius r of spiral line 12 decreases,the radius r,. of exhausthole l 1,the most part of the pressure energy of the compressed air isconverted to swirling velocity energy,and the remaining part of thepressure energy is converted to velocity energy in the axial direction.The air flows out of the exhaust hole 11 with axial flow velocity V,.,and when the radius r of the spiral line becomes equal to 1', which issmaller than radius r of the exhaust hole 11, the pressure of thecompressed air in the chamber 1 becomes equal to the ambient pressureand pressure P0 is entirely converted to tangential velocity U ,and thenall the swirling air flows out of the exhaust hole 11.

In this case, two kinds of vortex,namely forced vortex and naturalvortex,occur in the combustion chamber 1. In the case of the former, asshown with dotted line in FlG.3, near the axial center of the combustionchamber 1, the tangential velocity decreases in linear proportion to thedecrease of the radius. Namely,there is a tendency for that velocitygradient du/dr to become constant,and the pressure thereof is higher onthe outer side and lower on the inner side because of a centrifugalforce effect, and thus,the forced vortex zone E is formed. On the otherhand, in the case of the latter, as shown in FIG. 4, between the outerside of the forced vortex E and the inner surface wall 14 of thecombustion chamber 1, the tangential velocity increases with decrease ofthe radius according to the law of natural vortex,where m7 constant, andpressure along the radius is higher on the outer side and lower on theinner side, and thus a natural vortex zone F is formed.

Various features clarified by these experiments and analysis aboutvortex combustors are therefore as follows.

1. Easy ignition of the mixture of air and fuel can be carried out inthe forced vortex zone of the combustion chamber. 1

The forced vortex E rotates without producing relative movement in itsinner side as if the forced vortex is in the condition of a columnarsolid rod,and the tangential velocity at the axial center of the forcedvortex E becomes zero. The fuel is then injected into the forced vortexE in its radial direction from the fuel injection nozzle 9 provided nearthe axial center of the combustion chamber 1, and by means ofdischarging an electric spark from the ignition device 7, fuel is easilyignited silently. This is caused by the fact that the relative velocitybetween the fuel and the air is nearly zero in the forced vortex,whichis the essential condition for easy ignition.

In the case of this vortex combustor A, the circumference of the forcedvortex E is surrounded not by the solid wall but by the natural vortexF,so explosive noise does not occur.

2. It is possible to cause local combustion in the forced vortex E zoneof the combustion chamber,and stable combustion without the blowout ofthe flame can be carried out in a wide range of the air-fuel ratio.

The flame appearing in the forced vortex E is formed as a rotatingcolumnar shape, and this rotating flame is very stable as if it existsin a rotating cylinder having an inside wall surface which correspondsto the boundary surface'lS separating the forced vortex E-from thenatural vortex F.

When only a small amount of fuel is supplied into the combustion chamberof the ,vortex combustor A, a rotating columnar flame occurs in theforced vortex E having a short length in its axial direction,and itslength gradually increases as the fuel flow increases, and it burns toreach to the exhaust hole of the combustion chamber 1. Therefore, in thecase of this type of combustion, the combustion operation is completedwithin the forced vortex zone and in this condition, the'combustionchamber is partially used,sothe high intensity combustion is not carriedout.

When the fuel being supplied is increased even. more,the rotatingcolumnar flame spreads into the zone of the natural vortex F surroundingthe forced vortex v As there exists a large tangential velocity gradientdu/dx in the natural vortex, perfect mixing of the air and the fueltakes place, resulting in a violent combustion. But the transition ofthe rotating columnar flame in the forced vortex to the violent swirlingflame in the natural vortex can be obtained when the design of thecombustor is suitable, that is,the diameter of the exhaust hole 11- mustbe chosen rather larger and the cross-sectional area of the air inlethole 3 must be suitably smaller.

3. Combustion gas is recirculated by the reverse'flow produced in theforced vortex,and it becomes able'to operate with low exhaust emissions.

Thus, the forced vortex E rotates without relative movement taking placebetween the fuel and the air- ,and the pressure in the forced vortex Ebecomes higher on its outer side and lower in its central part becauseof the centrifugal force effect. Also, the pressure becomes equal to theambient pressure at the part of the outer circumference radius r of theforced vortex E, and pressure in the central part becomes lower thanambient pressure,and the ambient air is introduced within the centralpart of the forced vortex E through the exhaust hole 11.

4. As the fuel stays for a long period of time in the combustionchamber, due to the swirling motion of the compressed air and fuel,thecombustion efficiency can be increased.

5. Because within the zone of the natural vortex,fuel and air are burnedin a condition of perfect mixing,the fuel is completely burned at a hightemperature,- whereby combustion efficiency and combustion intensity canbe increased.

When compressed air is supplied from the air inlet hole 3, which openstangentially along the inner peripheral surface 4 of the combustionchamber 1, and rotates in the combustion chamber as shown in FIG. l,itspressure energy is gradually converted to velocity energy to increasethe tangential velocity u. As the radius r of the spiral line of airmovement becomes smaller,the rotating angular velocity w u/r becomeslarger.

The rotating angular velocity at the point of any radius r is w and thatat an adjacent point of radius r +Ar is w +Aw. In this case, A w has aminus value, since increasing radius results in decreasing velocity, andbecause of this difference A w, a slip phenomenon occurs. The perfectmixing of air and fuel is promoted by distortion due to this slipphenomenon. Namely, in the natural vortex,the velocity gradient du/dr isvery large near the forced vortex E because the tangential velocity uvaries greatly in this zone,as shown in FIG.3. When a fuel lump or solidpiece of fuel 16 is supplied into the natural vortex F,the fuel lump 16is subjected to a shearing force due to slip caused by the difference ofthe rotating angular velocity at the outer part of the lump where theradius r is large and that at the inner part where the radius r issmall. The fuel lump is thus atomized into very small pieces and isentirely mixed with air to a perfect mixing condition. On thecontrary,in the forced vortex E, as shown in FIG. 3, the fuel lump 16 isplaced where the velocity gradient du/dr is constant and slip does notoccur, as if the lump is placed in a rotating solid rod,andtherefore,the fuel lump rotates by itself and does not receive anyshearing force,so that the fuel lump 16 is not atomized into smalpieces.

Therefore, if the air-fuel ratio is correct or stoichiometric, forexample, the ratio of the air flow rate wa to the hydrocarbon fuel flowrate wf is chosen as :1 by weight,the mixture burns'completely in thecondition of perfect mixing in the natural vortex F in which slipphenomenon occurs.

When the difference between rotating angular velocity of the forcedvortex E and the natural vortex F at the boundary surface becomes largerthan a certain constant value,flame in the forced vortex E is blown outat the boundary surface,and the flame is not able to be transferred intothe natural vortex F. This face was also recognized by the experiments.

This transition is done more easilyas the ratio D /D between the innerdiameter D, of the combustion chamber 1 and the diameter D of theexhaust hole 11 increases,and as the ratio Si/D D between thecrosssectional area Si of the air inlet hole 3 and D,D

- VPo, so that the transition of flame from the forced vortex E into thenatural vortex F becomes difficult,if the ratio D /D of the diameter ofthe exhaust hole 11 to the inner diameter of the combustion chamber 1decreases and the air flow rate w increases.

In case the transition of combustion from the forced vortex E into thenatural vortex F is difficult, a sheath of blue flame occurs around theouter surface of the rotating columnar flame,and the flame goes out ofthe exhaust hole 11 of the combustion chamber 1. In this case,even ifthe fuel is increased,the flame only goes out of the combustion chamber1, and combustion is not transferred to the natural vortex zone.

It is known from the above description that combustion must be operatedin the forced vortex in the case where a weak mixture of air and fuelhas a large air-tofuel ratio, and that combustion must be operated inthe natural vortex in the case of a correct mixture of air and fuel,where the air-to-fuel ratio is nearly equal to the theoretical ratio, inorder to obtain a combustor which is operative over a wide range ofmixture ratios wa/wf.

From the studies of the conventional vortex combustors, it was observedthat fuel supplied from the axial center of the combustion chamber 1 isalways burned to produce a rotating columnar flame in the forced vortex,but it was also observed that the combustion is not 1 automaticallytransferred into the natural vortex zone. When fuel flow increases whileair flow being supplied tangentially into the combustion chamber 1 iskept v still further, the rotating columnar yellow flame separates fromthe fuel injector and becomes surrounded by blue flame extending in theaxial direction, and at last, a thin twisted columnar yellow flameoccurs within the combustion chamber 1 and' a flat disc type flame ofmixed color of blue and yellow exists from the exhaust hole 11 of thecombustion chamber 1, and becomes a stable in this condition. Theserotating columnar flames are always confined in the forced vortex and donot invade the natural vortex zone.

Taking into consideration the various points described above, variousexperiments have been conducted to clarify these observedcharacteristics, and from such studies the vortex combustor of thepresent invention having structure of various superior characteristicshas been provided.

The vortex combustor of the present invention thus comprises a firstcombustion unit having a cylindrical wall and an end wall on one end ofthe cylindrical wall thereof for forming a first combustion chamber, asecond combustion unit having a cylindrical wall and an end wall-on oneend of its cylindrical wall for forming a second combustion chamber, aconnecting part having a throttled opening for integrally connecting theother end of the two combustion units, at least one inlet means providedto the first combustion unit for introducing gas therethroughtangentially into the first combustion chamber, a fuel supplying deviceand an igniting device provided in the first combustion unit oppositethe connecting part and positioned near the central In the vortexcombustor of the present invention, the rotating columnar combustion ofyellow flame is carried out in the forced vortex zone in the firstcombustion chamber, and is projected from the connecting part into thesecond combustion chamber, and immediately after this process, itspreads into the natural vortex zone of the second combustion. chamber,where it is transformed into a circumferential swirling combustionautomatically and rapidly so that stable and violent combustion can becarried out, having very high com bustion efficiency and combustionintensity in a wide range of air-fuel ratio. Thus, difficulty ofignition of the mixture of air and fuel, blow-out of combustion flame,local overheating in the combustion chamber, and the like which were thedefects encountered in the various conventional combustors, can besolved.

Now, the structure of the vortex combustor of the present invention'willbe explained in detail according to certain embodiments thereof, and thecombustion state realized by the combustion in the forced vortex zone inthe combustion chamber being transferred to the natural vortex zoneautomatically and rapidly, will also be explained.

As shown in FIGS. to 8, a first outer cylindrical member 18 and a secondouter cylindrical member 19 are axially connected end-to-end to form anouter cylinder 17. The diameters of these two cylinders are usuallyequal, while the respective lengths thereof in their axial directionsare different from one another. On the outer circumferential edges 24 ofthe open parts 20, 21 and 22, 23, which open in the axial direction ofthe first and the second outer cylindrical members 18 and 19,respectively, integral flanges 26 being perforated with a plurality ofattaching holes 25 arranged in a circular array are provided forconnection to other parts. On the end surfaces of open parts '20 and 23of the first and second outer cylindrical members 18 and 19,respectively, disc type end plates 27 and 28 are secured by suitablemeans, such as bolts 29, nuts, or the like, through attaching holes 25'perforated in the outer circumferential edges of the end plates 27 and28 which correspond to the attaching holes 25 in the end flanges 26. Onthe other hand, an annular plate type throttle plate 31, having aconnecting hole 30 coaxially with the outer cylinder 17, is fixed byfixing members 29 through attaching holes in its circumferential edgecorresponding to attaching holes 25 at the circumferential edge of theouter cylinder, being disposed in a vertical plane with respect to theaxial direction of the outer cylinder between the end surface of theopen part 21 of the first outer cylindrical member 18 and the endsurface of the open part 22 of the second outer cylindrical member 19,which are disposed face-to-face mutually.

An inner cylinder 32 is coaxially inserted into the outer cylinder 17.One end of the cylinder 32 is closed, and the other end is open. Theouter diameter of the inner cylinder 32 is made smaller than the innerdiameter of the outer cylinder 17 and also is made smaller than theinner diameter of the connecting hole 30 of the throttle plate 31.Between the outer cylinder 17 and the inner cylinder 32, on oppositesides of the throttle plate 31, there are formed an annular chamber 33and a mixing chamber 34, the volume of the mixing chamber 34 being madesmaller than that of the annular chamber 33.

The annular chamber 33 and the mixing chamber 34 are mutually connectedby the connecting hole 30 which provides an annular passage between thethrottle plate 31 and the inner cylinder 32. An inlet hole 37 isprovided in the wall 35 of cylindrical member 18 in such a manner thatthe axial direction thereof coincides with the tangential direction ofthe inner peripheral. surface 33' of the annular chamber 33, so thatcompressed air may be conducted into the annular chamber 33 through asupplying passage 36 connected with a compressed air supply. in theouter cylinder wall part 38forming the mixing chamber 34, an outlet hole40 is provided in such a manner that the axial direction thereofcoincides with the tangential direction of the inner peripheral surface34 of the mixing chamber 34, so that combustion gas, ignited and burnedin the inner cylinder 32, may be exhausted out through an exhaustpassage 39 connecting with the mixing chamber 34. The outer side of theclosed end 41 of the inner cylinder 32 is attached to one end of asealed annular bel lows 44 which is fixed to the open end 43 of theouter cylinder 18 side of an open hole 42 perforated in the central partof the end plate 27, to permit stretching of the inner cylinder in itsaxial direction due to heat expansion, and to prevent leakage from theannular chamber 33. A plurality of radial supporting members 46 areattached integrally to the outer cylinder 17 for supporting the innercylinder 32 in coaxial relation with the outer cylinder 17, evenif theinner cylinder moves in its axial direction.

In the inner cylinder 32, there are formed a first combustion chamber 49and a second combustion chamber 50 axially aligned therewith, andthe'volume of chamber 50 is made to be larger than that of chamber 49.These chambers are divided by a first connecting part 48 having an innerdiameter smaller than that of the inner diameter of the inner cylinder32. A plurality of connecting holes 53 are provided in thecircumferential side wall 51 of the first combustion chamber 49 forconnecting the inside part of the first combustion chamber 49 with theannular chamber 33 the'reabout, the holes being made to openthereinto sothat their axial direction coincides with the tangential direction ofthe inner circumferential circle 52 of the first combustion chamber 49.At the axial center of side wall 54 of the closed end 41 of the firstcombustion chamber 49, the ignition device 7 is provided being connectedwith an ignition energy source. The ignition part 6 projects into thefirst combustion chamber 49, and the fuel injection nozzle 9 is disposedalong side. This valve 9 connects with the fuel supply source, notshown, and its injection hole 8 is made open so that its axial directionis corresponding to the axial direction of the first combustion chamber49. The second combustion chamber 50 connecting with the firstcombustion chamber 49 through the connecting part 48 at one end, has anopen end 47 at its other end which connects with the mixing chamber 34through a throttled open part 55 having an end plate 551 thereon. Thepart 55 is formed to have an inner diameter smaller than that of innercylinder 32 while being coaxial therewith, while at the same time beinglarger than that of the first connecting part 48. An annular cover plate57 of head cut conical shape is provided in the end plate 28 between theopen port 47 of the second combustion chamber 50 case, high efficiencyand high intensity combustion are t in demand and a great amount of airflow is necessary. Hereafter, the present invention will be explainedwith respect to an embodiment designed for gas turbines in automobiles.

A gas turbine G foran automobile includes an air compressor C, the heatexchanger H, a vortex combustor A, and a turbine T. The air compressor Ccomprises an impeller vane 61 and a diffuser vane 63. The impeller vane61 is mounted on an axle 60 rotatably driven by a generator or astarting motor through a driving gear, not shown, for introducing hightemperature air. On the other hand, the diffuser vane 63 is attached toa side wall 62 of the compressor C, with an upper flow' side 64 of thecompressor C being connected with an air inlet opening 65 forintroducing air into the compressor C. The lower flow side 66 of the aircompressor C is connected with a compressed air conducting passage 67 ofthe heat exchanger H in order to introduce compressed air from the aircompressor C to the heat exchanger H. In the heat exchanger H, the airof low temperature and high pressure from the air compressor C receivesheat radiation of the combustion gas of high temperature and lowpressure, and is converted to air of high temperature and high pressurein the grid type compressed air inlet passage 67. Combustion gasisintroduced through passages 68, having first been ignited and burned inthe vortex combustor A, and having carried out expansion work in theturbine T. The passages 67 and 68 are isolated from each other in theheat exchanger H, and the outlet side 69 of the combustiongas-introducing passage 68 is connected to the outside atmosphere. Thus,in the case of the vortex combustor A the supply passage 36 thereof isconnected to the exhaust side 70 of the compressed air-introducingpassage 67 of the heat exchanger H through an intake conduit 71, and theexhaust passage 39 thereof is connected with an inlet openng 72 of theturbine T. The turbine T has a casing 75 provided with a supply passagepart 73 whichconnects with the exhaust passage 39 of the vortexcombustor A and an exhaust gas passage 74 through which the combustiongas is introduced to the grid type combustion gas-introducing pas- 1sage 68 of heat exchanger H. Also, the turbine T has a turbine wheel 76for the compressor provided on the axle 60 such that it is rotatable asa unit with the impeller vane 61 of the air compressor C, being disposedin mutually spaced coaxial relation, and has a nozzle 77 for the turbinewhich is attached to the casing 75 opposite the turbine 76.

A power turbine 81 is disposed coaxially with the compressing turbine 76in the casing 75 and a variable inlet nozzle 82 of increasingcross-section for the power turbine is disposed therebetween. A drivingwheel axis 78 being parallel with that of the turbine 76 is connected tothe turbine 81 via a set of reduction gears 79 and 80.

The operation of the gas turbine to which the vortex combustor of thepresent invention is applied will now be explained. When the gas turbineG is operating, air is introduced into the air compressor C through theair inlet hole 65, and is compressed by the impeller vane 61 anddiffuser vane 63 thereof. The air compressed by the diffuser vane isintroduced into the grid typecompressed air inlet passage 67 of the heatexchanger H, where it becomes air of high temperature and high pressure,by receiving heat radiation from the combustion gas being passed in thecombustion gasintroducing passage 68 which is provided adjacent thepassage 67, and then it is introduced into the annular chamber 33 of thevortex combustor A,, through the outlet 70, conduit 71 and passage 36,and finally the opening 37 of the vortex combustor A,.

Thus, compressed air of high temperature is introduced into the annularchamber 33 and is given a swirl ing movement therein, the center ofwhich corresponds to the central axis of the annular chamber 33, bymeans of the introducing hole 37 which opens into the chamber in such amanner that the axial direction thereof coincides with the tangentialdirection of the inner peripheral surface 33' of the annular chamber 33.

The swirling air of high temperature and high pressure flows between theinner side wall 35 of the outer cylinder 17 and the outer'side wall 45of the inner cylinder 32 in the annular chamber 33, toward the other endof the chamber, and is throttled by the connecting hole 30 of thethrottling plate 31 between the annular chamber 33 and the mixingchamber 34, then being introduced into the mixing chamber 34. Thus, theswirling compressed air of high temperature in the annular chamber 33 iscaused to have a pressure drop AP compared with the air in chamber 34 bymeans of the throttling operation of the throttle plate 31.

As shown in FIG. 10, the air also flows into the first combustionchamber 49 along the tangential direction of the inner peripheralsurface 52 thereoffrom the plural connecting holes 53 of the firstcombustion chamber 49 connected with the annular chamber 33, whereby theair therein is given a swirling motion, the center of which correspondsto the central axis of the first combustion chamber 49. The compressedair of pressure P0 being supplied to the first combustion chamber 49thus traces a spiral line, and is projected into the second combustionchamber 50 from the first connecting part 48 in the direction composingthe tangential velocity Ue and the axial velocity Ve. In this case, inthe first combustion chamber 49 the forcedside wall 52 of the firstcombustion chamber 49. The

pressure energy of the-swirling air flow forming the natural vortex F isgradually converted to velocity energy during its swirling movement, andaccording to the law of the natural vortex ur=constant, tangential velocity u increases in inverse proportion to the radius of the spiral liner, and finally, when the radius decreases to r which is smaller than theradius r of the connecting part 48, the pressure becomes equal to thatof the mixing chamber, and so, the pressure drop AP is entirelyconverted to tangential velocity Uc.

Therefore, the rotating air column, called the vortex eye, is formednear the axial center of the first combustion chamber 49, and the air inthe vortex eye becomes the forced vortex which rotates with littlerelative movement, and there occurs the phenomenon that in the outercircumference, pressure is high, and in the central part, pressure islow, due to the centrifugal force effect. The radius of the forcedvortex E is r,., and its pressure becomes lower than that of the outerair pressure, and then there occurs the phenomenon that the outer air isintroduced into the central part in the vortex eye by a reverserecirculating flow. The combustion gas, or exhaust gas, is introducedinto the central part of the forced vortex E from the second combustionchamber 50 through the first connecting part 48. By means of the fuelinjection nozzle 9 and the ignition device 7 provided near the axialcenter of the side wall 54 of the closed part 41 of the first combustionchamber 49, fuel is injected along the axial direction of the firstcombustion chamber 49, and an electric spark is generated periodicallyin the central part of the rotating air column of the forced vortex Eswirling around the central axis of the first combustion chamber 49. Inthe forced vortex E, a fuel lump is placed in the condition of theconstant velocity gradient du/dr, so that it rotates by itself withoutmutual relative movement between the fuel and air. The fuel lump isatomized into'small pieces by means of a shearing force, and graduallymixes with the air in the rotating air column of the forced vortex E,and rotates in the forced vortex E in the condition that its relativevelocity with the, air therein is almost zero. In this situation, thefuel mixture is easily ignited and burned by the electric spark of theignition device 7. The flame generated by the electric spark has littlevelocity in the axial direction, but has substantial velocity in thetangential direction, and it rotates such that there is substantially nomutual relative movement between the fuel and air. Thus, the flame doesnot blow out unlike the case of the various conventional combustors inwhich the combustion is carried out in the supplied air flow, andbecause the natural vortex F surrounds the forced vortex E at the timefuel is ignited and thereafter, an explosive noise does not occur, sinceit is much as if it is surrounded by a solid wall. The combustion in therotating air column of the forced vortex E is very stable and still,being a local rotating column combustion of yellow flame. According tothe experiments, this local combustion is very stable without blowouteven if the swirling velocity of the natural vortex F around the forcedvortex E is made larger, and the rotation speed of the forced vortex Eismade higher.

The combustion condition of the vortex combustor is shown in FIGS.llA-llF. Namely, when a little fuel flow is supplied into the firstcombustion chamber 49, a short rotating columnar flame appears in theforced vortex E, as shown in FIG. 11A. As fuel flow increases, as shownin FIG. 1 1B, the length of the rotating columnar flame in the axialdirection increases to reach to the first connecting part 48 of thefirst combustion chamber 49, and then the combustion flame spreads intothe second combustion chamber 50.

Next, as shown in FIGS. 11C and 11D, the rotating columnar flame spreadsradially as well as axially in the second combustion chamber 50, in thezone of the natural vortex F surrounding the forced vortex E. The fuelis atomized to thin small pieces and mixes perfectly with the air in theswirling flow of large velocity gradient in the natural vortex F, for inthis flow the mixture is subject to the shearing force occuring becauseof the difference of the rotating angular velocity along the radius,thus a slip characteristic.

The mixture of air and fuel in the condition of molecule mixture istransmitted by the combustion flame from the first combustion chamber49, and it can be burned at the highest temperature and with highintensity near the inner circumferential wall of the second combustionchamber 50. Thus, both high combustion efficiency and high combustionintensity can be realized. As shown in FIGS. 11E and 11F, the rotatingcolumnar flame, burning in the zone of the forced vortex E of the firstcombustion chamber 49, projects into the second combustion chamber 50from the first connecting part 48, and immediately after spreads in thezone of the natural vortex F of the second combustion chamber 50, bothaxially and radially, and thus is converted to swirling combustion inthe circumferential part so that the combustion can be fully carriedout, and since the combustion flame reaches the inner side wall surfaceof the second combustion chamber 50, the side wall of the secondcombustion chamber 50 is heated to a high temperature by the combustiontherein. In the vortex combustor of the present invention, the cylinder32 providing combustion chambers 49 and 50 is disposed in radiallyspaced relation within the outer cylinder l7, and a swirling air flow isintroduced between the inner side wall of the outer cylinder 17 and theouter side wall of the inner cylinder 32, which define the annular space33. The side wall of the second combustion chamber- 50 is thereforecooled by this swirling air, so that the temperature of the side wallcan be held down to prevent damage thereto from overheating. Unlikethevarious conventional combustors, it is unnecessary to provide alimitation on the combustion conditions such as to maintain a determinedgap between the inner side wall surface and the combustion flame inorder to prevent overheating damage of the side wall of the combustionchamber. Therefore, the second combustion chamber 50 can be used withgreater efficiency, and the swirling combustion in the circumferentialpart thereof can be carried out such that the combustion flame can reachthe inner side wall of the second combustion chamber at its highesttemperature. In this case, the high temperature combustion gas isintroduced into the mixing chamber 34 from the open port 47 in thesecond connecting part 55 of the second combustion chamber 50. Thecombustion gas is then recycled by reverse flow in the second combustionchamber 50 as the pressure in the central part of the zone of the forcedvorted E becomes low because of the cover plate 56 disposed oppositeport 47.

Thus, the flame temperature can be lowered and also the generation ofharmful nitrogen oxide gascan be markedly prevented because the invasionof air from mixing chamber 34 into the second combustion chamber 50 canbe blocked.-

The swirling gas discharged from the open port 47 of the secondcombustion chamber strikes against the cover plate 56 and has its flowdirection radially turned. I

During the swirling flow between the cover plate 56 and the end plate551 of the throttled connecting part 55, the tangential velocity ofexhaust gas gradually decreases and the pressure increases by thediffuser action. Thus the pressure loss in the combustor due to theswirling flow is somewhat recovered.

The exhaust gas mixes with the air in the mixing chamber 34 being passedthereinto through the throttle plate 31. The swirling flow of the mixingair passed through the throttle plate 31 helps to keep the temperaturedistribution in the mixing chamber uniform. Moreover, the cover plate 56is heated to a high temperature because its surface facing the port 47is directly contacted by the flowing combustion gas, but since thepposite surface of the cover plate 56 is exposed to the outeratmospheric air.directly, its temperature is prevented from rising toosignificantly..Also, because its contact area with outer atmosphere isquite large because of its configuration, the cooling effect of thecovered part 57 to prevent overheating caused by the combustion gas, andtherefore damage thereto, is greatly enhanced. I

i The combustion gas is cooled to a certain temperature after the mixingoperation in the mixing chamber 34, and the gas is conducted outtangentially along the inner peripheral surface 34' of the mixingchamber 34 from the outlet hole 40 which is made open in such a mannerthat its axial direction coincides with the tangential direction of theinner peripheral surface 34' of the mixing chamber 34. The combustiongas then flows into the turbine nozzle 77 for the compressor of theturbine T and into the variable nozzle 82 for output therefrom.

Expansion work is carried out in the turbine T, by means of the energyof the combustion gas, and thus the turbine 76 for the compressor andthe power turbine 81 are rotatably driven. After the expansion work inthe turbine T has been completed, the combustion gas is conductedthrough the grid type gas conducting passage 68 of the heat exchanger H,for pre-heating the compressed air which passes through the compressedair conducting passage 67 isolatedly disposed in the heat exchanger fromthe combustion gas conducting passage 68, and then the combustion gas isexhausted from the exhaust hole 69 of the combustion gas conductingpassage 68 through an exhaust pipe, not shown.

Furthermore, in a vortex combustor constructed according to the presentinvention, preferably values can be selected according to the variousobjects and uses.

These values are as follows:

1. The ratio of the diameter D of the first connecting part. 48 to theinner diameter D, of the first combustion chamber 49, D lD 2. The ratioof the cross-sectional area S; of the connecting hole of the firstcombustion chamber to the product of the inner diameter D of the firstcombustion chamber and the diameter D of the first connecting part, S,/DD

' 3. The values of D and D in a relation of D, D where D, is thediameter of the open port 47 of the second combustion chamber 50 and Dis the diameter of the connecting part 48 of the first combustionchamber; and

4. The ratio of the diameter D, of the open part of the secondcombustion chamber 50 to the inner diameter D of the second combustionchamber, D /D Namely by our experiments and analysis with the vortexcombustors of the present invention, it was found that D /D should beless than or equal to 0.6, and S /D D should be less than 0. l

Thus, the rotating columnar flame can be positively provided in thefirst combustion chamber 49 in the zone of the forced vortex where thepressure loss is very small, because of the constant velocity gradienttherein. On the contrary, in the case of the second com-.

bustion chamber 50, it was found that the diameter D, of the open port47 should be made to be larger than the diameter D of the connectingpart 48 of the first combustion chamber 49, and the ratio between theinner diameter D of the second combustion chamber 50 and the diameter Dof its open port 47,- D /D should roughly be taken to be less than 0.8.Thus, the rotating columnar flame burning in the zone of the forcedvortex E in the first combustion chamber 49 is projected into the secondcombustion chamber 50 from the first connecting part 48, where the flameimmediately spreads radially into the zone of the natural vortex F inthe second combustion chamber 50, and can then be transmitted to thecircumferential and swirling combustion state automatically and rapidly;In the case of the combustors of the present embodiment, the conductinghole is not provided at the second combustion chamber to conduct air forcombustion, but when a connecting hole of sectional area S is provided,in other embodiments, the condition S IDQD S ,/D,D must be satisfied.

The vortex combustor of the present invention has various superioreffects which will be described hereinafter: I

l. The fuel injection nozzle and the ignition, device are providedclosely to one another in the region of the forced vortex E near thecentralaxis of the first combustion chamber 49 and the fuel is suppliedin a mist condition in a wide angle being directed in the axialdirection of the first combustion chamber. The fuel is easily ignited bythe electric spark without any explosive noise, even if the naturalvortex F surrounding the forced vortex E rotates'very rapidly. If thecombustion flame is blown out by some factor, the fuel can be ignitedvery easily again.

2. Since the fuel stays for a long period of time in the first and thesecond combustion chambers because of the swirling flow pattern, thecombustion efficie'ncy becomes as high as nearly percent, whether thecombustion condition in the combustion chamber is the yellow flamecombustion or the blue flame combustion.

3. The fuel and air are mixed together perfectly in the zone of thenatural vortex F in the-second combustion chamber 50, so thecombustion-intensity becomes large when the blue flame combustionspreads into the entire second combustion chamber.

4. From the rotating columnar combustion in the forced vortex zone inthe first combustion chamber 49, to the high. intensity blue flamecombustion in the zone in the second combustion chamber of the naturalvortex, complete combustion is carried out in a continuous and stablecondition, so an air-fuel ratio of very wide range, Wa/Wf E l5-300,which is wider than that of the usual combustors, Wa/ Wf E 17-23 ispermitted.

5. The cover plate 56 is disposed between the open port 47' of thesecond combustion chamber 50 and the outlet hole 40 of the mixingchamber 34. The cover plate 56 part also is near and opposite to theopen port 47. Thus, the combustion gas is exnitrogen-oxide gas isprevented from occurring.

The volume of re-circulating gas depends on the ratio D,/D of thediameter D, of the open port to the inner diameter D; of the secondcombustion chamber and it increases as the ratio D,/D becomes larger.Generally speaking, if complete combustion is carried out in thecombustors of high efficiency, no harmful gas such as hydrocarbon andcarbon monoxide exists, but when the combustion flame temperatureishigh, nitrogen oxides will be produced. As complete combustion alsotakes place in the vortex combustor of the present invention, nohydrocarbon and no carbon monoxide exists. But, the likely production ofnitrogen oxides also disappears because of the recirculation of theexhaust gas, by which the flame temperature is lowered to about l,600 C.

6. Moreover, a high intensity combustion is carried out in thecombustion chamber of the vortex combustor, so that all kind of fuels,such as gas fuel,

gasoline, lamp oil, light oil, heavy oil and the like, can be equallyburned in a wide range of air-fuel ratio.

7. As shown in FIGS. 1 1Al lC, in the forced vortex of the firstcombustion chamber, local combustion is carried out using a centralcombustion chamber, without directly contacting the outside wall of thecombustion chamber. Therefore, high temperature combustion from 1,500 to3,000 C can be carried out by mixing oxygen in fuel for practical use.In this case, heat caused by heat radiation at the side walls ofthefirst and the second combustion chambe rs 49 and 50, is cooled by meansof the swirling air flow flowing into the annular chambers 33 and 34 inthe outer cylinder 17 surrounding the inner cylinder. Therefore, theside wall surface of the combustion chamber is not damaged by overheat-The combustion flame in the first and the second combustion chambers 49and 50 of the vortex combustor rotates rapidly, so the temperaturedistribution becomes uniform along the circular direction of eachcombustion chamber, and unlike the case of the usual combustors, localoverheating does not occur.

9. The combustion gas is discharged from the open 10. In the case of theconventional combustors, a first air and a second air are supplied frommany air holes, so various experience and many experiments are necessaryto determine the number, the diamev 16 ter, and the arrangement of theair holes, but the vortex combustors of the present invention can beeasily designed;

While in the first embodiment described in detail above, the vortexcombustor of the present invention is shown being applied as separateapparatus from the gas turbine engine itself for automobiles, thepresent invention is not limited to this arrangement and type of turbinefor a gas turbine engine, but it may be made for any type. For example,the present combustor can be applied to small and simple gas turbineengines-for aviation. The combustor itself is combined into an engine inone body, and the length in the axial direction of the combustor is madeshort. in this case, the vortex combustor of the present invention canbe applied, as shown in FIG. 12, by varying the design and size ofvarious components of the vortex combustor from those of the firstembodiment.

Now referring to FIG. 12, a second embodiment of the present inventionwill be explained.

' A gas turbine engine 6,, is composed of an air compressor C, a vortexcombustor A, and a turbine T, all

being disposed respectively in coaxial relation in an engine casing ofcircular cylindrical design. The air compressor C and the turbine T arerespectively fixed to a rotating axle 86 for rotation therewith as aunit. An annular outer cylinder 170, of the vortex combustor A of whichboth ends are closed, is provided between the air-compressor C and theturbine T, and both side circumferential walls thereof are supportedby'the engine casing 85, while the inner circumferential wall thereof isaxially supported by the rotating axle 86. An annular inner cylinder320, one end thereof being closed and the other end being open, iscoaxially disposed within the outer cylinder 170. Between the inner sidewall of the outer cylinder and the outer side wall of the inner cylinder320, a throttled plate 310 is provided, and an annular chamber 330 and amixing chamber 340, being connected with each other, are formed by thethrottled plate 310. An annular conducting hole 370 is open at a sidewall part 350 of the outer cylinder 170 forming the annular chamber 330.The hole 370 connects with the air compressor C and air is conductedthrough hole 370 along a tangential direc: tion of the innercircumferential circle of the annular chamber. An annular exhaust hole400 opens at the side wall part of the outer cylinder 170 forming themixing chamber 340. The combustion gas is thus conducted out of theinner cylinder 320 to the mixing chamber 340, and then is exhausted fromthe mixing chamber 340 to the turbine T through the hole 400.

The annular inner cylinder 320 is divided into a first combustionchamber 490 and a 'second combustion chamber 500 by an annularconnecting part 480 which is disposed between a closed end part 410 andan open end part 470 thereof. The first combustion chamber 490 iscomposed of a pre-combustion section 87 and a combustion section 88, thepre-combustion section 87 and the combustion section 88 being mutuallyconnected by means of a connecting hole 530. This connecting hole 530conducts the combustion gas from the pre-combustion section 87 along atangential direction of the inner circumferential circle of thecombustion section 88, with one end being closed while the other end isopen.

The ignition device 7 and the fuel injection nozzle 9 of this embodimentare disposed side-by-side near the axial center of the closed end of thepre-combustion section 87. The ignition device.7 is connected with anignition energy source, and its ignition part projects into the insideof pre-combustion section 87. The fuel injection nozzle 9 connects witha fuel supply source, and its jet hole 8 opens toward the pre-combustionsection 87,. A plurality of air inlet holes 3 are provided in thepre-combustion section 87, the insideof the air inlet holes 3 connectingwith the annular chamber 330 and conducting air along a tangentialdirection of the inner circumferential circle of the pre-combustionsection 87. On the other hand, an annular open port 470 is provided inthe second combustion chamber 500, which connects with the mixingchamber 340, and its outer diameter is the outer circumferential edge ofthe inner cylinder 320. Also, a closed wall 90 is formed in the secondcombustion chamber 500 in the same plane with the annular open port 470,so that the closed wall 90 covers the area near the axial center of thesecond combustion chamber 500, and at the same time, a second annularconnecting part 550 is formed near the said annular open port 470.

According to this second embodiment of the present invention, asdescribed above, near the central part of the rotating air column of theforced vortex in the precombustion section 87 of the first combustionchamber 490, fuel from the fuel jet injection nozzle 9 is mixed withswirling air flow and it is ignited and burned by generatingperiodically an electric spark with the ignition device 7. Then, arotating columnar flame in the region of the forced vortex is jettedinto the combustion section 88 of the first combustion chamber 490through the connecting hole 530 At this time, the flame is given theswirling movement along a tangential direction of the innercircumferential circle of the combustion section 88. Immediately afterthis process, the rotating columnar combustion carried out in the zoneof the forced vortex E in the combustion section 88 is jetted into thesecond combustion chamber 500 from the first annular connecting part480, and then is widened in the zone of the natural vortex F in thesecond combustion chamber 500, where it is converted to thecircumferential swirling combustion automatically and rapidly. Thus,high intensity combustion can be carried out at the highest temperature.The inner circumferential wall of the second combustion chamber 500 -isused as the reaction surface. The combustion efficiency and thecombustion intensity in this case, are very high, and therefore, theapparatus of the second embodiment has a good effect, essentially thesame as the case of the first embodiment. Moreover, the vortex combustoritself can be constructed to be of small size, and thus a compact andsimplified gas turbine engine can be obtained.

In the first and the second embodiments of the present invention, theinlet holes and the connecting holes are made to open tangentially alongthe inner circumferential circle of the annular chamber, or the firstcombustion chamber, so that air for combustion, to be supplied into theannular chamber, or the first combustion chamber, of the vortexcombustor, is given a swirling movement the center of which iscorresponding to the axial center of the annular chamber, or the firstcombustion chamber. For this purpose, any construction can'be employedif it is within the effect of the present invention.

For example, air for combustion can be conducted tangentially into theannular chamber, or the first combustion chamber, by giving it swirlingmovement through a spiral wing, a tangential groove, or a tangentialpipe.

In the first embodiment, the first and the second combustion chambersare disposed mutually in series and in coaxial relation, and in thesecond embodiment the first combustion chamber is disposed in a verticalor perpendicular plane with respect to the axial direction of the secondcombustion chamber. But the disposition is not limited to the casementioned above. Namely, any design variation can be permitted about thedisposition and formation of the various components of the vortexcombustor of the present invention, according to its objects and itspurposes as long as it is within the range of the effect of the presentinvention.

biles and for aircraft, which are described herein with relation to thefirst and second embodiments. For example, they can be used as variouscombustors using heat energy, such a boilers, burners, steam motors,heating apparatus and water boilers. They can also be used as thecombustors for heat motors using mechanical energy which is convertedfrom heat energy, such as various steam turbines, gas turbines, jetengines and steam engines, which can be employed in many fields, forexample, for aircraft, ships, motor vehicles, electric generation andfor industrial motive force in various works.

Obviously, many modifications and variations of the present inventionare possible in light of these teachings. It is to be understoodtherefore, that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described herein.

. Accordingly, what is claimed as new and desired to be secured byLetters Patent of the United States is:

l. A vortex-combustor comprising:

a first combustion unit having a cylindrical wall and an end wall on oneend thereof for forming a first combustion chamber;

a second combustion unit having a cylindrical wall and an end wall onone end thereof for forming a second combustion chamber; I

a connecting part having a throttled opening for integrally connectingsaid two combustion units;

at least one inlet means in said first combustion unit forintroducinggas tangentially into said first combustion chamber;'

a fuel supplying device and an igniting device connected to said firstcombustion unit positioned near the central axis of said firstcombustion chamber; and

said second combustion chamber having a throttled open part in saidsecond combustion unit opposite said connecting part.

2. A vortex combustor according to claim 1, furthe comprising:

an outer casing having a cylindrical wall and two closed end walls;

means for supporting said first and second combustion units in saidouter casing in spaced relation thereto;

at least one inlet passage means provided in said outer casing forintroducing gas tangentially within said outer casing; and

at least one outlet passage means provided on said outer casing fordischarging combustion gas from said outer casing.

3. A vortex combustor according to claim' 1, wherein said first andsecond combustion units are disposed coaxially in series.

4. A vortex combustor according to claim 1, further comprising:

a cover plate positioned adjacent said second combustion unit in opposedrelation to said throttled open part thereof.

A vortex combustor according to claim 2, further comprising:

a throttle member having at least one opening hole therein disposedbetween said outer casing and second combustion unit adjacent saidthrottled open part, being arranged to divide the annular space betweensaid outer casing and said first and second combustion units into anannular chamber connected to said inlet passage means and a mixingchamber connected to said outlet passage means.

6. A vortex combustor according to claim 2, further comprising:

a cover plate positioned adjacent said second combustion unit in opposedrelation to said throttled open part thereof.

7. A vortex combustor according to claim 6, further comprising: i

a throttle member having atleast one opening hole therein disposedbetween said outer casing and said cylindrical wall of said secondcombustion unit Y near said throttled open part thereof, and beingarranged to divide the annular space between said outer casing and saidfirst and second combustion units into-an annular chamberconnected tosaid inlet passage means and a mixing chamber connected to said outletpassage means and an opening between said throttled open part of secondcombustion unit and said cover plate within said outer casing.

8. A vortex combustor according to claim 3, further comprising: I

an outer casing having a cylindrical wall and two closed end walls beingdisposed about said first and second combustion units in surroundingrelation therewith; at least one inlet passage means provided in saidouter casing for introducing gas tangentially within said outer casing;and at least one outlet passage means provided in said outer casing fordischarging combustion gas from said outer casing. 9. A vortex combustoraccording to claim 8, further comprising:

a throttle member having at least one opening hole therein disposedbetween said outer casing and sec-' ond combustion unit, near saidthrottled open part thereof, being arranged to divide the annular spacebetween said outer casing and said first and second combustion unitsinto an annular chamber connected to said inlet passage means and amixing chamber connected to said outlet passage means.

5 10. A vortex combustor according to claim 9, further comprising:

a cover plate positioned adjacent said second combustion unit in opposedrelation to said throttled open part thereof.

11. A vortex combustor according wherein:

said outer casing is composed of first and second cylinders-each havingoutward extending flanges on both ends thereof;

one of said end walls of said outer casing being a circular plate fixedon the flange of one end of said first cylinder;

the other end of said first cylinder and one end of said second cylinderbeing fixed together by their flanges with said throttle memberinterposed therebetween;

the other of said end walls of said outer casing being said cover plateintegrally fixed to the flange of the other end of said second cylinder;

said inlet passage meansis a pipe tangentially arranged into one end ofsaid first cylinder at a position near said circular plate; V

said outlet passage means isa pipe tangentially arranged into one end ofsaid second cylinder at a position near said cover plate; and

said first and second integrally connected combustion units arepositioned in the interior of said outer casing, in such a manner thatsaid end wall of said first combustion unit is supported elastically tosaid circular plate and said throttled open part of said secondcombustion unit is in opposed relation to said cover plate.

12. A vortex combustor according to claim 10,

wherein:

said outer casing and said first and second combus tion units areannular cylinders.

13. A vortex combustor according to claim 1, where to claim 10,

said first and second combustion units are disposed such that the axesof said two cylindrical walls intersect at a right angle.

14. A vortex combustor according to claim 13, further comprising: i

an outer casing having a cylindrical wall and two closed end wallssurrounding said first and second combustion units;

at least one inlet passage meansin said outer casing for introducing gastangentially into said outer casing; and

at least one outlet passage means in said outer casing for dischargingcombustion gas from said outer casing.

15. A vortex combustor according to claim l4, further comprising:

a throttle member having at least one opening hole disposed between saidouter casing and second combustion unit near said throttled open part ofsaid second combustion unit and being arranged to form an annularchamber connected to said inlet passage means and a mixing chamberconnected to said outlet passage means within said outer casing.

16. A vortex combustor according to claim 15, furwherein: thercomprising: the ratio of the diameter of said throttled opening of a coer plate position jace t a d opp t Said said connecting part to theinner diameter of said throttled open part of said second combustionunit. fi combustion i i l s h or equal to Q6; the diameter of saidthrottled open part in said sec- A 3? combustor according Claim 0ndcombustion unit is larger than or equal to the ther compnsmg: v I Idiameter of said throttled opening of said connecta wall memberextending substantially radially from ing part; and

the cylindrical wall of said second combustion unit and forming athrottled opening surrounded by the 10 inner wall surface thereof fordividing said second combustion chamber into a combustion chamberconnected to said first combustion chamber through said throttledopening of said connecting part and a combustion chamber having saidthrottled open part.

18. A vortex combustor according to claim 17,

the ratio of the cross-sectional area of said at least one inlet meansin said first combustion unit to the product of the inner diameter ofsaid first combustion unit and the diameter of said throttled opening ofsaid connecting part is less than 0.1.

20. A vortex combustor according to claim 19,

wherein:

the ratio of the diameter of said throttled open part in said secondcombustion unit to the inner diamewhcrcin: i

said outer casing and said second combustion unit te 0f Said SecondCombustion Unit is less than or are annular cylinders. 7 equal to 0.8.

19. A vortex combustor according to claim 1,

1. A vortex combustor comprising: a first combustion unit having acylindrical wall and an end wall on one end thereof for forming a firstcombustion chamber; a second combustion unit having a cylindrical walland an end wall on one end thereof for forming a second combustionchamber; a connecting part having a throttled opening for integrallyconnecting said two combustion units; at least one inlet means in saidfirst combustion unit for introducing gas tangentially into said firstcombustion chamber; a fuel supplying device and an igniting deviceconnected to said first combustion unit positioned near the central axisof said first combustion chamber; and said second combustion chamberhaving a throttled open part in said second combustion unit oppositesaid connecting part.
 2. A vortex combustor according to claim 1,further comprising: an outer casing having a cylindrical wall and twoclosed end walls; means for supporting said first and second combustionunits in said outer casing in spaced relation thereto; at least oneinlet passage means provided in said outer casing for introducing gastangentIally within said outer casing; and at least one outlet passagemeans provided on said outer casing for discharging combustion gas fromsaid outer casing.
 3. A vortex combustor according to claim 1, whereinsaid first and second combustion units are disposed coaxially in series.4. A vortex combustor according to claim 1, further comprising: a coverplate positioned adjacent said second combustion unit in opposedrelation to said throttled open part thereof.
 5. A vortex combustoraccording to claim 2, further comprising: a throttle member having atleast one opening hole therein disposed between said outer casing andsecond combustion unit adjacent said throttled open part, being arrangedto divide the annular space between said outer casing and said first andsecond combustion units into an annular chamber connected to said inletpassage means and a mixing chamber connected to said outlet passagemeans.
 6. A vortex combustor according to claim 2, further comprising: acover plate positioned adjacent said second combustion unit in opposedrelation to said throttled open part thereof.
 7. A vortex combustoraccording to claim 6, further comprising: a throttle member having atleast one opening hole therein disposed between said outer casing andsaid cylindrical wall of said second combustion unit near said throttledopen part thereof, and being arranged to divide the annular spacebetween said outer casing and said first and second combustion unitsinto an annular chamber connected to said inlet passage means and amixing chamber connected to said outlet passage means and an openingbetween said throttled open part of second combustion unit and saidcover plate within said outer casing.
 8. A vortex combustor according toclaim 3, further comprising: an outer casing having a cylindrical walland two closed end walls being disposed about said first and secondcombustion units in surrounding relation therewith; at least one inletpassage means provided in said outer casing for introducing gastangentially within said outer casing; and at least one outlet passagemeans provided in said outer casing for discharging combustion gas fromsaid outer casing.
 9. A vortex combustor according to claim 8, furthercomprising: a throttle member having at least one opening hole thereindisposed between said outer casing and second combustion unit, near saidthrottled open part thereof, being arranged to divide the annular spacebetween said outer casing and said first and second combustion unitsinto an annular chamber connected to said inlet passage means and amixing chamber connected to said outlet passage means.
 10. A vortexcombustor according to claim 9, further comprising: a cover platepositioned adjacent said second combustion unit in opposed relation tosaid throttled open part thereof.
 11. A vortex combustor according toclaim 10, wherein: said outer casing is composed of first and secondcylinders each having outward extending flanges on both ends thereof;one of said end walls of said outer casing being a circular plate fixedon the flange of one end of said first cylinder; the other end of saidfirst cylinder and one end of said second cylinder being fixed togetherby their flanges with said throttle member interposed therebetween; theother of said end walls of said outer casing being said cover plateintegrally fixed to the flange of the other end of said second cylinder;said inlet passage means is a pipe tangentially arranged into one end ofsaid first cylinder at a position near said circular plate; said outletpassage means is a pipe tangentially arranged into one end of saidsecond cylinder at a position near said cover plate; and said first andsecond integrally connected combustion units are positioned in theinterior of said outer casing, in such a manner that said end wall ofsaid first combustion unit is supported elastically to said circularplate and said thRottled open part of said second combustion unit is inopposed relation to said cover plate.
 12. A vortex combustor accordingto claim 10, wherein: said outer casing and said first and secondcombustion units are annular cylinders.
 13. A vortex combustor accordingto claim 1, where said first and second combustion units are disposedsuch that the axes of said two cylindrical walls intersect at a rightangle.
 14. A vortex combustor according to claim 13, further comprising:an outer casing having a cylindrical wall and two closed end wallssurrounding said first and second combustion units; at least one inletpassage means in said outer casing for introducing gas tangentially intosaid outer casing; and at least one outlet passage means in said outercasing for discharging combustion gas from said outer casing.
 15. Avortex combustor according to claim 14, further comprising: a throttlemember having at least one opening hole disposed between said outercasing and second combustion unit near said throttled open part of saidsecond combustion unit and being arranged to form an annular chamberconnected to said inlet passage means and a mixing chamber connected tosaid outlet passage means within said outer casing.
 16. A vortexcombustor according to claim 15, further comprising: a cover platepositioned adjacent and opposed to said throttled open part of saidsecond combustion unit.
 17. A vortex combustor according to claim 15,further comprising: a wall member extending substantially radially fromthe cylindrical wall of said second combustion unit and forming athrottled opening surrounded by the inner wall surface thereof fordividing said second combustion chamber into a combustion chamberconnected to said first combustion chamber through said throttledopening of said connecting part and a combustion chamber having saidthrottled open part.
 18. A vortex combustor according to claim 17,wherein: said outer casing and said second combustion unit are annularcylinders.
 19. A vortex combustor according to claim 1, wherein: theratio of the diameter of said throttled opening of said connecting partto the inner diameter of said first combustion unit is less than orequal to 0.6; the diameter of said throttled open part in said secondcombustion unit is larger than or equal to the diameter of saidthrottled opening of said connecting part; and the ratio of thecross-sectional area of said at least one inlet means in said firstcombustion unit to the product of the inner diameter of said firstcombustion unit and the diameter of said throttled opening of saidconnecting part is less than 0.1.
 20. A vortex combustor according toclaim 19, wherein: the ratio of the diameter of said throttled open partin said second combustion unit to the inner diameter of said secondcombustion unit is less than or equal to 0.8.